Skull and cranium are two important skeletal parts that protect the brain and supports other soft tissues located in the head, but a difference can be noted between them based on their structure. The main difference between the skull and cranium is that skull is a complex structure containing 22 bones while cranium is a subdivision of the skull, containing only 8 bones. In this article, further differences between skull and cranium will be highlighted.
What is Skull?
The human skull is a complex structure consisting of 22 bones which mainly comprises cranial bones (8) and facial bones (14). The skull is located on the atlas of the vertebral column. The main cavity of the skull that encloses the brain is called cranium cavity. The other several cavities found within the skull are called sinuses that accommodate the hearing and equilibrium structures. The great architectural design of the skull reflects its many functions. Most importantly, it provides protection for the most important organ of the nervous system; the brain. Moreover, the skull is involved in speech, breathing, vision, and hearing. Facial bones provide surfaces to muscle attachments and make passages to respiratory and digestive systems.
What is Cranium?
The cranium is a subdivision of the skull that consists of 8 bones, which enclose the brain. The eight bones include ethmoid, frontal, occipital, parietal (2), sphenoid, and temporal (2). Among these bones, parietal bones and the frontal bone are the largest. The main role of the cranium is to protect the brain. In addition, cranium provides a surface for the attachment of muscles that helps the movement of the head and supports the sense organs located in the head. The walls of cranial walls are composed of two plates. The edge of each bone is joined with an adjacent bone edge through fibrous interlocking joints called ‘sutures’. The sutures are unique to cranial bones.
What is the difference Skull and Cranium?
Definition of Skull and Cranium
Skull: Skull refers to the bones of the head collectively.
Cranium: It is the bony portion of the skull that holds the brain.
Features of Skull and Cranium
Number of bones
Skull: Skull consists of 22 bones.
Cranium: Cranium consists of 8 bones called cranial bones.
Function
Skull: Skull protects the brain, provides a surface for muscle attachments and holds sensory organs for vision, hearing, speech and vision.
Cranium: Cranium mainly protects the brain and provides surfaces for facial muscle attachments.
Cavities
Skull: Skull has the cranial cavity and smaller sinuses.
Cranium: Cranium makes the cranial cavity in which the brain is located.
Image Courtesy:
“Human skull side simplified (bones)” by LadyofHats Mariana Ruiz Villarreal – (Public Domain) via Wikimedia Commons
“Gray194” by Henry Vandyke Carter – Henry Gray (1918) Anatomy of the Human Body (See “Book” section below)Bartleby.com: Gray’s Anatomy, Plate 194. (Public Domain) via Commons